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Molecular mechanisms underlying microglial sensing and phagocytosis in synaptic pruning 被引量:2
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作者 Anran Huo Jiali Wang +6 位作者 Qi Li Mengqi Li Yuwan Qi Qiao Yin Weifeng Luo Jijun Shi Qifei Cong 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1284-1290,共7页
Microglia are the main non-neuronal cells in the central nervous system that have important roles in brain development and functional connectivity of neural circuits.In brain physiology,highly dynamic microglial proce... Microglia are the main non-neuronal cells in the central nervous system that have important roles in brain development and functional connectivity of neural circuits.In brain physiology,highly dynamic microglial processes are facilitated to sense the surrounding environment and stimuli.Once the brain switches its functional states,microglia are recruited to specific sites to exert their immune functions,including the release of cytokines and phagocytosis of cellular debris.The crosstalk of microglia between neurons,neural stem cells,endothelial cells,oligodendrocytes,and astrocytes contributes to their functions in synapse pruning,neurogenesis,vascularization,myelination,and blood-brain barrier permeability.In this review,we highlight the neuron-derived“find-me,”“eat-me,”and“don't eat-me”molecular signals that drive microglia in response to changes in neuronal activity for synapse refinement during brain development.This review reveals the molecular mechanism of neuron-microglia interaction in synaptic pruning and presents novel ideas for the synaptic pruning of microglia in disease,thereby providing important clues for discovery of target drugs and development of nervous system disease treatment methods targeting synaptic dysfunction. 展开更多
关键词 COMPLEMENT immune signals microglia molecular signal synapse elimination synapse formation synapse refinement synaptic pruning
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基于PN-YOLO v8s-Pruned的轻量化三七收获目标检测方法
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作者 王法安 何忠平 +2 位作者 张兆国 解开婷 曾悦 《农业机械学报》 EI CAS CSCD 北大核心 2024年第11期171-183,共13页
为实现三七联合收获作业过程中的自适应分级输送和收获状态实时监测,本文针对三七根土复合体特征和复杂田间收获工况,提出一种基于YOLO v8s并适用于Jetson Nano端部署的三七目标检测方法。在YOLO v8s对三七准确识别的基础上,针对其新的... 为实现三七联合收获作业过程中的自适应分级输送和收获状态实时监测,本文针对三七根土复合体特征和复杂田间收获工况,提出一种基于YOLO v8s并适用于Jetson Nano端部署的三七目标检测方法。在YOLO v8s对三七准确识别的基础上,针对其新的模型结构特性,利用通道剪枝算法,制定相应剪枝策略,保证模型精度的同时提升实时检测性能。采用TensorRT推理加速框架将改进模型部署至Jetson Nano,实现了三七目标检测模型的灵活部署。试验结果表明,改进后的PN-YOLO v8s-Pruned模型在主机端的平均精度均值为93.71%,参数量、计算量、模型内存占用量分别为原始模型的39.75%、57.69%、40.25%,检测速度提升44.26%,与其他目标检测模型相比,本文改进模型在计算复杂度、检测精度和实时性方面具有更好的综合检测性能。在Jetson Nano端部署后,改进模型检测速度达18.9 f/s,较加速前提升2.7倍,较原始模型提升5.8 f/s。台架试验结果表明,4种输送分离收获作业工况下三七目标检测的平均精度均值达87%以上,不同输送分离收获作业工况和不同流量等级下的目标三七计数平均正确率分别达92.61%、91.76%。田间试验结果表明,三七目标检测平均精度均值达84%,计数平均正确率达88.11%,图像推理速度达31.0 f/s。模型检测性能和计数效果能够满足复杂田间收获工况下目标三七的检测需求,可为基于边缘计算设备的三七联合收获作业自适应分级输送系统和收获作业质量监测系统提供技术支撑。 展开更多
关键词 三七 复杂收获作业工况 目标检测 通道剪枝 Jetson Nano YOLO v8s
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An Investigation of Frequency-Domain Pruning Algorithms for Accelerating Human Activity Recognition Tasks Based on Sensor Data
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作者 Jian Su Haijian Shao +1 位作者 Xing Deng Yingtao Jiang 《Computers, Materials & Continua》 SCIE EI 2024年第11期2219-2242,共24页
The rapidly advancing Convolutional Neural Networks(CNNs)have brought about a paradigm shift in various computer vision tasks,while also garnering increasing interest and application in sensor-based Human Activity Rec... The rapidly advancing Convolutional Neural Networks(CNNs)have brought about a paradigm shift in various computer vision tasks,while also garnering increasing interest and application in sensor-based Human Activity Recognition(HAR)efforts.However,the significant computational demands and memory requirements hinder the practical deployment of deep networks in resource-constrained systems.This paper introduces a novel network pruning method based on the energy spectral density of data in the frequency domain,which reduces the model’s depth and accelerates activity inference.Unlike traditional pruning methods that focus on the spatial domain and the importance of filters,this method converts sensor data,such as HAR data,to the frequency domain for analysis.It emphasizes the low-frequency components by calculating their energy spectral density values.Subsequently,filters that meet the predefined thresholds are retained,and redundant filters are removed,leading to a significant reduction in model size without compromising performance or incurring additional computational costs.Notably,the proposed algorithm’s effectiveness is empirically validated on a standard five-layer CNNs backbone architecture.The computational feasibility and data sensitivity of the proposed scheme are thoroughly examined.Impressively,the classification accuracy on three benchmark HAR datasets UCI-HAR,WISDM,and PAMAP2 reaches 96.20%,98.40%,and 92.38%,respectively.Concurrently,our strategy achieves a reduction in Floating Point Operations(FLOPs)by 90.73%,93.70%,and 90.74%,respectively,along with a corresponding decrease in memory consumption by 90.53%,93.43%,and 90.05%. 展开更多
关键词 Convolutional neural networks human activity recognition network pruning frequency-domain transformation
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Pruning Techniques for Prunus mume
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作者 JI Hao 《Journal of Landscape Research》 2024年第3期66-69,共4页
Prunusmumehas high ornamental value,and its maintenance and management should be more meticulous,with pruning being an important task.Pruning can make P.mume more robust,reduce the occurrence of diseases and pests,mai... Prunusmumehas high ornamental value,and its maintenance and management should be more meticulous,with pruning being an important task.Pruning can make P.mume more robust,reduce the occurrence of diseases and pests,maintain a good shape,and promote more flowering,further improving its ornamental value.The difficulty of pruning lies in flexibly adopting suitable pruning methods according to the time of the tree,which requires understanding the impact of pruning operations on the growth and flowering of P.mume,as well as some techniques in pruning operations.This paper introduces the botanical characteristics of P.mume,common pruning methods and achievable effects of P.mume,and suitable time for using various methods,and analyzes the possible consequences and reasons of some incorrect operations.Moreover,corresponding correct practices are provided,which can provide reference for standardized pruning of P.mume,thereby reducing or avoiding losses caused by improper operation. 展开更多
关键词 Prunusmume pruning Viewing TECHNOLOGY
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结合通道剪枝和通道注意力的轻量型车辆点云补全网络
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作者 杨晓文 冯泊栋 +3 位作者 韩慧妍 况立群 韩燮 何黎刚 《计算机工程与应用》 北大核心 2025年第1期232-242,共11页
针对现有的点云补全网络多关注于补全的精度而忽视补全效率问题,提出了一种轻量型点云补全网络来准确、高效地修复自动驾驶中的不完整车辆点云。为了提高网络推理效率,采用一种高效的一次性通道剪枝技术提高网络的补全效率;在特征提取阶... 针对现有的点云补全网络多关注于补全的精度而忽视补全效率问题,提出了一种轻量型点云补全网络来准确、高效地修复自动驾驶中的不完整车辆点云。为了提高网络推理效率,采用一种高效的一次性通道剪枝技术提高网络的补全效率;在特征提取阶段,网络加入通道注意力模块,将加权特征与全局特征拼接,通过两层多维特征信息提取,得到最终的特征向量;将特征向量传入双解码器结构中,分别通过全连接层和多层感知机生成稠密的粗糙点云和输入点云偏差值;将粗糙点云与输入点云偏差值相加得到最终的精细化完整点云。在PCN数据集和KITTI数据集上进行实验,实验结果表明在补全缺失车辆信息的实时性上有着显著的提升,并且在补全精度上也有不错的表现。 展开更多
关键词 点云补全 通道剪枝 通道注意力 轻量型 深度学习
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Analysis on Fuji Apple Tree Structures and Related Factors under Different Pruning Modes 被引量:1
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作者 郝婕 索相敏 +4 位作者 李学营 魏亮 王献革 鄢新民 冯建忠 《Agricultural Science & Technology》 CAS 2017年第12期2528-2531,2535,共5页
To determine the correlations between the tree structuresof Fuji apple with different pruning modes and each factor, the data about 3 tree structures which were free spindle short shoot, free spindle long shoot and sl... To determine the correlations between the tree structuresof Fuji apple with different pruning modes and each factor, the data about 3 tree structures which were free spindle short shoot, free spindle long shoot and slenderspindle short shoot in Xingtang County of Hebai Province were investigated, then by SPSS anal- ysis, the correlations between the taperingness and each growth factor of inserted small branch were compared. The results showed that the taperingness of central trunk of free spindle dwarf-shoot Fuji apple treeshad negative correlations with each factor of inserted small branch, while the taperingness of central trunk of free spin- dle long-shoot Fuji apple treeshad positive correlations with each factor of inserted small branch, the taperingness of central trunk of slenderspindle short-shootFuji ap- ple treeshad negative correlation with total thickness of inserted small branch, but had positive correlations with other factors. This study can provide a scientifictheo- retical basis for the pruning technology of high-density planting trees grafting by dwarfing self-rooted rootstock. 展开更多
关键词 pruning Fuji apple Tree structures Analysis of related factors
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面向无人机协同定位的机载深度计算编译优化
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作者 熊康 刘思聪 +3 位作者 王宏涛 高元 郭斌 於志文 《计算机科学与探索》 北大核心 2025年第1期141-157,共17页
随着无人机技术快速发展,在定位信号缺失的情况下进行无人机定位成为一个研究难题。而近几年图神经网络的出现与发展,为解决这一难题提供了一种新的解决思路。然而在资源受限的无人机端侧部署图神经网络面临着无人机算储资源受限及实时... 随着无人机技术快速发展,在定位信号缺失的情况下进行无人机定位成为一个研究难题。而近几年图神经网络的出现与发展,为解决这一难题提供了一种新的解决思路。然而在资源受限的无人机端侧部署图神经网络面临着无人机算储资源受限及实时性难以满足等挑战。提出面向无人机协同定位的机载深度计算编译优化方法。采用了一种轻量化的时间图卷积神经网络模型,该时间图卷积网络由图卷积网络和门控递归单元组成,将无人机群的空间依赖性和无人机位置变化的时间依赖性同时加以考虑,对无人机群位置进行精确的预测;针对该模型在时间图卷积网络上的冗余特性,提出了基于逆向Cuthill-McKee图重排和基于双深度确定性策略梯度的全局自适应剪枝算法。在保证无人机群坐标精确预测的同时,不仅能提高数据在主存的空间局部性,加速模型的运算速度,而且能够对模型进行自适应的非结构化剪枝,降低模型的存储复杂度。实验结果表明,相对于已有的时间图卷积神经网络模型,编译优化后的轻量化时间图卷积神经网络模型在保留78.8%准确率的同时,模型计算时间降低37.9%,模型的平均剪枝率达到90.3%。 展开更多
关键词 时间图卷积网络 协同定位 通道剪枝 图重排算法 深度确定性策略梯度
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Analysis on Apple Tree Structures by Free Spindle Pruning Mode
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作者 郝婕 索相敏 +3 位作者 李学营 王献革 鄢新民 冯建忠 《Agricultural Science & Technology》 CAS 2016年第10期2238-2241,共4页
To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "F... To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "Fuji", free spindle long shoot "Fuji", free spindle "Huaguan" were investigated in Xingtang County of Hebei Province by SPSS analysis. The results showed that the stem taperingness on free spindle short shoot "Fuji" was in negative correlation with central shaft, but the correlation was not significant. While the stem taperingness on free spindle long shoot "Fuji" was in positive correlation with central shaft, but the correlation was not significant either. The stern taperingness on free spindle "Huaguan" was in negative correlation with central shaft, and the correlation between the stem taperingness and the central shaft total length was significant at the level of 0.01. The results.provided scientific theoretical basis for guiding the dwarfing rootstocks close planting apple tree pruning technology. 展开更多
关键词 APPLE Free spindle pruning mode Structure analysis
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改进的基于FFT pruning的窄带高分辨率频谱算法 被引量:3
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作者 王琰 万群 杨万麟 《计算机工程与应用》 CSCD 北大核心 2007年第26期54-55,141,共3页
提出一种改进的基于FFT pruning的窄带高分辨率频谱计算方法。该方法是对Sreenivas's FFT pruning算法和Nagai的利用频移变换的FFT pruning算法的推广。同时提出输出点分级思想,可实现任意窄带上非2的整数幂次频点输出。该算法比Sre... 提出一种改进的基于FFT pruning的窄带高分辨率频谱计算方法。该方法是对Sreenivas's FFT pruning算法和Nagai的利用频移变换的FFT pruning算法的推广。同时提出输出点分级思想,可实现任意窄带上非2的整数幂次频点输出。该算法比Sreenivas's FFT pruning算法具有更小的计算量和更简单的信号流图。 展开更多
关键词 FFT pruning 窄带 频移
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一种改进的FFT Pruning算法及其在塔康载波频率测量中的应用 被引量:1
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作者 彭大国 李治安 +2 位作者 李晓明 裴文林 牛诚旻 《南京邮电大学学报(自然科学版)》 北大核心 2015年第1期66-71,共6页
提出了一种改进的FFT Pruning算法。将Nagai提出的频移思想和Alves提出的辅助矩阵思想结合起来,对信号流图和辅助矩阵进行简化。对输出频点数与辅助矩阵列数的关系进行研究,降低了辅助矩阵的大小,并推导出辅助矩阵的表达式。将改进后的... 提出了一种改进的FFT Pruning算法。将Nagai提出的频移思想和Alves提出的辅助矩阵思想结合起来,对信号流图和辅助矩阵进行简化。对输出频点数与辅助矩阵列数的关系进行研究,降低了辅助矩阵的大小,并推导出辅助矩阵的表达式。将改进后的算法运用到塔康载波频率测量中,先用少点数的FFT进行频率粗搜索,再用改进的FFT Pruning算法进行频率精测。仿真结果表明,改进算法能在运算量不大的情况下实现对塔康载波频率的高精度测量。 展开更多
关键词 FFT pruning 辅助矩阵 塔康 频率测量
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Effects of Pruning Treatments on Yield and Economic Benefits of Pepper in Greenhouse during Long-season Cultivation 被引量:2
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作者 袁野 杨剑 +2 位作者 童辉 彭莹 袁祖华 《Agricultural Science & Technology》 CAS 2016年第3期593-595,共3页
In the Yangtze River region, thepepper long-season cultivation needs oversummer pruning. Inorder to study the effects of different pruning treatments on growth of over-summer grown pepper, three differentpruning treat... In the Yangtze River region, thepepper long-season cultivation needs oversummer pruning. Inorder to study the effects of different pruning treatments on growth of over-summer grown pepper, three differentpruning treatments were applied to pepper seedlings, such as treatment one(re-growth pruning), treatment two(four stems) and treatment three(multi-stem pruning) with no pruning as control(CK).The results showed that themulti-stem pruning treatment enabling the plant to maintain the good plant type for high yield and reduce thevirus disease to improve the marketability of pepper fruits, compared with the other two pruning treatments;andthe yield and economic benefit were increased by 15.8% and 19%, compared with the control, respectively. Ingeneral the multi-stem pruning was the best for over-summer pepper cultivation. 展开更多
关键词 pruning treatment PEPPER Over-summer cultivation
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一种改进的基于FFT Pruning算法的快速实现方法 被引量:1
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作者 李忠慧 曾毓敏 +1 位作者 尹晓琦 吴婷婷 《南京师范大学学报(工程技术版)》 CAS 2005年第4期42-45,共4页
针对文献[5]提出的FFT Prun ing算法作了一些改进,得到了只计算FFT频谱中部分频点谱值的改进的快速实现方法.根据输入输出数据的结构特点,利用辅助矩阵和数据复制等手段,降低了FFT Prun ing算法实现的复杂度,提高了FFTPrun ing算法实现... 针对文献[5]提出的FFT Prun ing算法作了一些改进,得到了只计算FFT频谱中部分频点谱值的改进的快速实现方法.根据输入输出数据的结构特点,利用辅助矩阵和数据复制等手段,降低了FFT Prun ing算法实现的复杂度,提高了FFTPrun ing算法实现的灵活性.将改进后的FFT Prun ing算法用C语言实现并在DSP集成开发环境CCS下的C5402 D evice S im-u lator上运行.在相同条件下,再运行一般意义上的FFT算法和文献[5]中算法所对应的C程序,统计3种方法的运行时间并比较他们的效率.仿真结果表明:在相同的条件下,改进后的算法在快速准确地得到相关频谱值的同时,运算时间明显少于另外两种方法.同时,对输入输出端所取数据的长度也没有任何限制. 展开更多
关键词 FFT pruning算法 算法实现 数字信号处理 频谱分辨率
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Effect of pruning intensity on soil moisture and water use efficiency in jujube(Ziziphus jujube Mill.) plantations in the hilly Loess Plateau Region, China 被引量:6
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作者 JIN Shanshan WANG Youke +2 位作者 WANG Xing BAI Yonghong SHI Leigang 《Journal of Arid Land》 SCIE CSCD 2019年第3期446-460,共15页
Jujube(Ziziphus jujube Mill.)is a traditional economic forest crop and is widely cultivated in hilly areas of the Loess Plateau,China.However,soil desiccation was discovered in jujube plantations.Pruning is recognized... Jujube(Ziziphus jujube Mill.)is a traditional economic forest crop and is widely cultivated in hilly areas of the Loess Plateau,China.However,soil desiccation was discovered in jujube plantations.Pruning is recognized as a water-saving method that can reduces soil water consumption.In this study,we monitored the jujube plots with control(CK),light(C1),medium(C2)and high(C3)pruning intensities during the jujube growing period of 2012-2015 to explore the effect of pruning intensity on soil moisture and water use efficiency(WUE)of jujube plantations in the hilly Loess Plateau Region.The results showed that pruning is an effective method for soil water conservation in jujube plantations.Soil moisture increased with increasing pruning intensity during the jujube growing period of 2012-2015.C1,C2 and C3 pruning intensities increased soil water storage by 6.1-18.3,14.4-40.0 and 24.3-63.3 mm,respectively,compared to CK pruning intensity.Pruning promoted soil moisture infiltration to deeper soil layer.Soil moisture infiltrated to soil depths of 240,280 and>300 cm under C3 pruning intensity,220,260 and 260 cm under C2 pruning intensity,200,240 and 220 cm under C1 pruning intensity,and 180,200 and 160 cm under CK pruning intensity in 2013,2014 and 2015,respectively.Soil water deficit was alleviated by higher pruning intensity.In 2013-2015,soil water change was positive under C2(6.4 mm)and C3(26.8 mm)pruning intensities but negative under C1(-20.5 mm)and CK(-40.6 mm)pruning intensities.Moreover,pruning significantly improved fresh fruit yield and WUE of jujube plants.Fresh fruit yields were highest under C1 pruning intensity with the values of 6897.1-13,059.3 kg/hm^2,which were 2758.4-4712.8,385.7-1432.1 and 802.8-2331.5 kg/hm2 higher than those under CK,C2,and C3 pruning intensities during the jujube growing period of 2012-2015,respectively.However,C3 pruning intensity had the highest WUE values of 2.92-3.13 kg/m3,which were 1.6-2.0,1.1-1.2 and 1.0-1.1 times greater than those under CK,C1 and C2 pruning intensities,respectively.Therefore,C3 pruning intensity is recommended to jujube plantations for its economic and ecological benefits.These results provide an alternative strategy to mitigate soil desiccation in jujube plantations in the hilly Loess Plateau Region,which is critical for sustainable cultivation of economic forest trees in this region. 展开更多
关键词 pruning intensity soil DESICCATION yield water use efficiency Ziziphusjujube Mill. LOESS Plateau
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东北地区李属(Prunes L.)植物导管分子形态结构研究 被引量:4
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作者 邹子瑜 谷利伟 张大维 《植物研究》 CAS CSCD 北大核心 2021年第1期4-11,共8页
利用扫描电子显微镜(SEM)和树脂铸型法对东北地区10种李属植物导管分子类型、纹孔式、穿孔板类型的微形态结构特征进行了观察,并测量管腔长度、宽度、尾端长度及端壁斜度角的量化数据。结果显示:在不同生境下该属同种植物的导管类型、... 利用扫描电子显微镜(SEM)和树脂铸型法对东北地区10种李属植物导管分子类型、纹孔式、穿孔板类型的微形态结构特征进行了观察,并测量管腔长度、宽度、尾端长度及端壁斜度角的量化数据。结果显示:在不同生境下该属同种植物的导管类型、尾端长度与穿孔板类型较为稳定。所观察的李属植物存在3种导管类型:螺纹、孔纹、网纹导管。除山杏、欧李、东北李3种植物中仅存在网纹与孔纹2种类型的导管外,其余7种植物普遍存在3种类型导管。螺纹加厚在该属导管分子中普遍存在。单穿孔板在李属所观察植物中普遍存在,仅在黑樱桃、毛樱桃和郁李中发现梯状穿孔板。仅在稠李、东北李、郁李及山杏中观察到相对原始的对列—互列同时存在的纹孔式,其余6种均为互列式纹孔式。根据结构分析,认为东北地区10种李属植物中,郁李最为原始,欧李最为进化。同时,发现管腔长度、宽度与端壁面积与生境显著相关。在对尾端长度测量发现,同种植物导管分子的尾端长度在不同生境下长度较为稳定,几乎没有变化,可作为微观植物分类学的分类依据。 展开更多
关键词 李属 导管分子 扫描电镜 形态结构
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Effect of first thinning and pruning on the individual growth of Pinus patula tree species 被引量:4
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作者 Edward Missanjo Gift Kamanga-Thole 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第4期827-831,共5页
The effect of first thinning and pruning on height, diameter at breast height (DBH), and volume growth was studied in individual trees of Pinus patula Schiede and Deppe in Chongoni Plantation, using four plots for t... The effect of first thinning and pruning on height, diameter at breast height (DBH), and volume growth was studied in individual trees of Pinus patula Schiede and Deppe in Chongoni Plantation, using four plots for thinning trials. Each of the plots was 0.5 ha and subjected to one of the fol- lowing silvicultural treatments: first thinning and pruning, first thinning and no pruning, pruning and no thinning, and control (no pruning and no thinning). The silvicultural treatments were randomized in four replicates. Fourteen years after planting, the following parameters were measured including total height, DBH, and volume. The highest DBH and volume growth was observed in thinning and pruning, while the highest growth in height was observed where there was pruning and no thinning. Clearly, both thinning and pruning are an important manage- ment option in pine species plantations in Malawi to maximize the increase in volume productivity. 展开更多
关键词 Pinus patula Thinning and pruning Diameter growth Height growth VOLUME
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Improved pruning algorithm for Gaussian mixture probability hypothesis density filter 被引量:8
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作者 NIE Yongfang ZHANG Tao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第2期229-235,共7页
With the increment of the number of Gaussian components, the computation cost increases in the Gaussian mixture probability hypothesis density(GM-PHD) filter. Based on the theory of Chen et al, we propose an improved ... With the increment of the number of Gaussian components, the computation cost increases in the Gaussian mixture probability hypothesis density(GM-PHD) filter. Based on the theory of Chen et al, we propose an improved pruning algorithm for the GM-PHD filter, which utilizes not only the Gaussian components’ means and covariance, but their weights as a new criterion to improve the estimate accuracy of the conventional pruning algorithm for tracking very closely proximity targets. Moreover, it solves the end-less while-loop problem without the need of a second merging step. Simulation results show that this improved algorithm is easier to implement and more robust than the formal ones. 展开更多
关键词 Gaussian mixture probability hypothesis density(GM-PHD) filter pruning algorithm proximity targets clutter rate
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Effects of Root Pruning on Non-Hydraulic Root-Sourced Signal, Drought Tolerance and Water Use Efficiency of Winter Wheat 被引量:5
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作者 MA Shou-chen LI Feng-min +3 位作者 YANG Shen-jiao LI Chun-xi XU Bing-cheng ZHANG Xu-cheng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第6期989-998,共10页
Two pot experiments were conducted to study the effects of root pruning at the stem elongation stage on non-hydraulic root-sourced signals (nHRS), drought tolerance and water use efficiency of winter wheat (Triticu... Two pot experiments were conducted to study the effects of root pruning at the stem elongation stage on non-hydraulic root-sourced signals (nHRS), drought tolerance and water use efficiency of winter wheat (Triticum aestivum). The root pruning significantly reduced the root weight of wheat, but had no effect on root/shoot ratio at the two tested stages. At booting stage, specific root respiration of root pruned plants was significantly higher than those with intact roots (1.06 and 0.94 mmol g-1 s-1, respectively). The soil water content (SWC) at which nHRS for root pruned plants appeared was higher and terminated lower than for intact root plants, the threshold range of nHRS was markedly greater for root pruned plants (61.1-44.6% field water capacity) than for intact root plants (57.9-46.1% field water capacity). At flowering stage, while there was no significant difference in specific root respiration. The SWCs at which nHRS appeared and terminated were both higher for root pruned plants than for intact root plants. The values of chlorophyll fluorescence parameters, i.e., the effective photosystem II quantum yield (F PS II ), the maximum photochemical efficiency of PS II (F v /F m ), coefficient of photochemical quenching (qP), and coefficient of non-photochemical quenching (NPQ), in root pruned plants were significantly higher than in intact root plants, 7 d after withholding of water. Root pruned plants had significantly higher water use efficiency (WUE) than intact root plants in well-watered and medium drought soil, but not in severe drought condition. In addition, root pruning had no significant effect on grain yield in well-watered and medium drought soil, but significantly decreased grain yield in severe drought condition. In conclusion, the current study showed that root pruning significantly altered nHRS sensitivity and improved WUE of winter wheat in well-watered and medium drought soil, but lowered drought tolerance of winter wheat in severe drought soil. This suggests a possible direction of drought- resistance breeding and potential agricultural measure to improve WUE of winter wheat under semiarid conditions. 展开更多
关键词 winter wheat root pruning non-hydraulic root-sourced signal (nHRS) root activity drought tolerance
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Nitrogen Mineralization of Prunings of Six N_2-Fixing Hedgerow Species in a Dry Valley of the Jinsha River 被引量:7
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作者 SUN HUI, TANG YA and ZHAO QIGUO Institute of Soil Science, the Chinese Academy of Sciences, Nanjing, 210008 (China) Chengdu Institute of Biology, the Chinese Academy of Sciences, Chengdu 610041 (China) 《Pedosphere》 SCIE CAS CSCD 2002年第1期25-31,共7页
A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or u... A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or used as mulch. The results indicated thatpruning N of the six hedgerow species was mineralized fast in thefirst week and then decreased slowly in the rest of the study period.When prunings were incorporated into soil, the amount of nitrogenmineralized by the end of the first week accounted for 69.9/100,58.2/100, 54.5/100, 43.0/100, 29.6/100 and 20.6/100 of the total N inprungins of Desmodium rensonii, Tephrosia candida, Leucaenaleucoephala, Albizia yunnanensis, Acacia dealbata, and Acaciamearnsii, respectively. 展开更多
关键词 contour hedgerow system MINERALIZATION N prunings
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Improved adaptive pruning algorithm for least squares support vector regression 被引量:4
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作者 Runpeng Gao Ye San 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第3期438-444,共7页
As the solutions of the least squares support vector regression machine (LS-SVRM) are not sparse, it leads to slow prediction speed and limits its applications. The defects of the ex- isting adaptive pruning algorit... As the solutions of the least squares support vector regression machine (LS-SVRM) are not sparse, it leads to slow prediction speed and limits its applications. The defects of the ex- isting adaptive pruning algorithm for LS-SVRM are that the training speed is slow, and the generalization performance is not satis- factory, especially for large scale problems. Hence an improved algorithm is proposed. In order to accelerate the training speed, the pruned data point and fast leave-one-out error are employed to validate the temporary model obtained after decremental learning. The novel objective function in the termination condition which in- volves the whole constraints generated by all training data points and three pruning strategies are employed to improve the generali- zation performance. The effectiveness of the proposed algorithm is tested on six benchmark datasets. The sparse LS-SVRM model has a faster training speed and better generalization performance. 展开更多
关键词 least squares support vector regression machine (LS- SVRM) pruning leave-one-out (LOO) error incremental learning decremental learning.
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连续滑动窗的递推-Pruning-FFT算法 被引量:1
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作者 王小军 周学科 宫世子 《西安邮电学院学报》 2004年第2期99-102,共4页
在信号谱线分析中,经常用到滑动窗的FFT计算,由于传统的FFT在N值较大和滑动步距较小时,计算量较大,在"实时"通信系统中难以实现,本文提出一种连续滑动窗的递推 PruningFFT算法,该算法充分利用了前窗的计算结果并将输入序列转... 在信号谱线分析中,经常用到滑动窗的FFT计算,由于传统的FFT在N值较大和滑动步距较小时,计算量较大,在"实时"通信系统中难以实现,本文提出一种连续滑动窗的递推 PruningFFT算法,该算法充分利用了前窗的计算结果并将输入序列转换为一个输入端仅有少数非零点的特殊序列,不仅降低了计算量,而且提高了使用的灵活性和实时性。 展开更多
关键词 滑动窗 递推-pruningFFT 信号谱线分析 离散傅立叶变换
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